Method of correcting pixel data and fluid ejecting apparatus

Abstract

A method for correcting pixel data and a fluid ejecting apparatus and are disclosed. The method for correcting pixel data in the fluid ejecting apparatus which relatively moves a nozzle array having nozzles for ejecting a fluid onto a medium and arranged in parallel in a predetermined direction, and the medium in a direction intersecting the predetermined direction, onto which the fluid is ejected from the nozzle array based on pixel data of the first number of gradations, while the nozzle array and the medium are relatively moved in the intersecting direction, the method includes converting original pixel data of the first number of gradations into pixel data of the second number of gradations higher than the first number of gradations; correcting the pixel data of the second number of gradations, of which the number of gradations is converted, by a correction value set for every pixel line data which is the plurality of pixel data lined up in a direction corresponding to the intersecting direction on the pixel data; and converting the pixel data of the second number of gradations which is corrected by the correction value into the pixel data of the first number of gradations.

1 . A method for correcting pixel data in a fluid ejecting apparatus which relatively moves a nozzle array having nozzles for ejecting a fluid onto a medium and arranged in parallel in a predetermined direction, and the medium in a direction intersecting the predetermined direction, onto which the fluid is ejected from the nozzle array based on pixel data of the first number of gradations, while the nozzle array and the medium are relatively moved in the intersecting direction, the method comprising:
 converting original pixel data of the first number of gradations into pixel data of the second number of gradations higher than the first number of gradations;   correcting the pixel data of the second number of gradations, of which the number of gradations is converted, by a correction value set for every pixel line data which is the plurality of pixel data lined up in a direction corresponding to the intersecting direction on the pixel data; and   converting the pixel data of the second number of gradations which is corrected by the correction value into the pixel data of the first number of gradations.   
     
     
         2 . The method for correcting pixel data according to  claim 1 , further comprising, in the original pixel data of second number of gradations, of which the number of gradations is converted from the original pixel data of the first number of gradations,
 distributing a gradation value expressed by the selected original pixel data among the original pixel data of the second number of gradations to the selected original pixel data and the original pixel data adjacent to the selected original pixel data to calculate averaged pixel data of the second number of gradations;   determining a correction value corresponding to the averaged pixel data of the second number of gradations; and   correcting the original pixel data of the second number of gradations by the determined correction value.   
     
     
         3 . The method for correcting pixel data according to  claim 1 , further comprising, in the original pixel data of second number of gradations, of which the number of gradations is converted from the original pixel data of the first number of gradations,
 distributing a gradation value expressed by the selected original pixel data among the original pixel data of the second number of gradations to the selected original pixel data and the original pixel data adjacent to the selected original pixel data to calculate averaged pixel data of the second number of gradations;   determining a correction value corresponding to the averaged pixel data of the second number of gradations; and   correcting the averaged pixel data of the second number of gradations by the determined correction value.   
     
     
         4 . The method for correcting pixel data according to  claim 2 , wherein the correction value is set for a plurality of gradation values in the second number of gradations. 
     
     
         5 . The method for correcting pixel data according to  claim 2 , wherein when the gradation value expressed by the selected original pixel data of the second number of gradations is distributed to the selected original pixel data and the original pixel data adjacent to the selected original pixel data, the gradation values which are distributed to the original pixel data spaced apart from the selected original pixel data at first distance are more than the gradation values which are distributed to the original pixel data spaced apart from the selected original pixel data at a second distance which is longer than the first distance. 
     
     
         6 . The method for correcting pixel data according to  claim 1 , wherein the correction value corresponding to the original pixel data of the second number of gradations, of which the number of gradations is converted from the original pixel data of the first number of gradations, is determined, and
 the original pixel data of the second number of gradations is corrected by the determined correction value.   
     
     
         7 . The method for correcting pixel data according to  claim 1 , when the pixel data of the second number of gradations which is corrected by the correction value is converted into the pixel data of the first number of gradations,
 a value related to a formation rate of dots corresponding to the gradation value expressed by the selected pixel data among the pixel data of the second number of corrected gradations is compared with a threshold value to determine existence of dot formation in the selected pixel data; and   a difference between the value related to the formation rate of the dots and the threshold value is distributed to the pixel data adjacent to the selected pixel data.   
     
     
         8 . A fluid ejecting apparatus comprising:
 (A) a nozzle array having nozzles for ejecting a fluid onto a medium and arranged in parallel in a predetermined direction;   (B) a moving mechanism relatively moving the nozzle array and the medium in a direction intersecting the predetermined direction; and   (C) a control unit that ejects the fluid from the nozzle array based on pixel data of the first number of gradations, while the nozzle array and the medium are relatively moved in the intersecting direction by the moving mechanism,   wherein original pixel data of the first number of gradations are converted into pixel data of the second number of gradations higher than the first number of gradations; the pixel data of the second number of gradations, of which the number of gradations is converted, are corrected by a correction value set for every pixel line data which is the plurality of pixel data lined up in a direction corresponding to the intersecting direction on the pixel data; and   the pixel data of the second number of gradations which are corrected by the correction value is converted into the pixel data of the first number of gradations.